/* BHNKC Vocab — dark, mobile-first, Word Out–style */
:root {
  --bg: #0b0b0c;
  --bg2: #111113;
  --card: #18181b;
  --card2: #202024;
  --border: #2a2a2f;
  --text: #f3f3f4;
  --muted: #9a9aa3;
  --dim: #6b6b74;
  --accent: #7b96ff;
  --accent-soft: rgba(123, 150, 255, 0.18);
  --green: #4ade80;
  --green-bg: #17331f;
  --red: #f87171;
  --red-bg: #3a1c1c;
  --amber: #fbbf24;
  --amber-bg: #3a2e12;
  --radius: 22px;
  --radius-sm: 14px;
  --nav-bg: rgba(11, 11, 12, .92);
  --heat1: #1e3a2a; --heat2: #22633a; --heat3: #2e9a54;
  --nav-h: 64px;
  color-scheme: dark;
  --maxw: 900px;   /* iPad-first: wide enough for 2–4 column grids */
}
* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html, body { margin: 0; padding: 0; background: var(--bg); color: var(--text); }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", "PingFang TC",
    "Microsoft JhengHei", "Noto Sans TC", sans-serif;
  font-size: 16px; line-height: 1.5;
  padding-bottom: calc(var(--nav-h) + env(safe-area-inset-bottom));
  min-height: 100vh;
}
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; cursor: pointer; border: 0; background: none; }
input, select, textarea { font: inherit; color: inherit; }
.hidden { display: none !important; }
.muted { color: var(--muted); }
.dim { color: var(--dim); }
.small { font-size: 13px; }
.tiny { font-size: 12px; }
.center { text-align: center; }
.row { display: flex; align-items: center; gap: 10px; }
.between { justify-content: space-between; }
.wrap { flex-wrap: wrap; }
.grow { flex: 1; min-width: 0; }
.mt { margin-top: 14px; }
.mb { margin-bottom: 14px; }
.ellipsis { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* ---------- top bar ---------- */
#topbar {
  position: sticky; top: 0; z-index: 20;
  display: flex; align-items: center; justify-content: space-between;
  max-width: var(--maxw); margin: 0 auto; padding: 14px 18px 8px;
  background: linear-gradient(var(--bg) 70%, transparent);
}
.brand { font-size: 17px; letter-spacing: .2px; color: var(--muted); }
.brand b { color: var(--text); }
.topbar-actions { display: flex; gap: 8px; align-items: center; }
.icon-btn {
  width: 44px; height: 44px; border-radius: 50%; background: var(--card); border: 1px solid var(--border);
  font-size: 20px; display: inline-flex; align-items: center; justify-content: center;
}
.icon-btn:active { transform: scale(.94); }
.pill {
  display: inline-flex; align-items: center; gap: 6px; padding: 8px 14px; border-radius: 999px;
  background: var(--card); border: 1px solid var(--border); font-size: 15px;
}
.streak-pill b { font-size: 17px; }

/* ---------- layout ---------- */
#view { max-width: var(--maxw); margin: 0 auto; padding: 4px 18px 24px; }
.page-title { font-size: 26px; font-weight: 700; margin: 8px 0 12px; letter-spacing: -.2px; }
.section-title { font-size: 13px; font-weight: 600; letter-spacing: .06em; color: var(--muted); text-transform: uppercase; margin: 22px 0 10px; }
.card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 16px 18px; margin-bottom: 12px;
}
.card.tight { padding: 12px 16px; }
.card.clickable:active { background: var(--card2); }
.big-card { padding: 22px 20px; }
.back-btn {
  display: inline-flex; align-items: center; gap: 4px; padding: 8px 16px 8px 12px; border-radius: 999px;
  border: 1px solid var(--border); background: var(--card); font-size: 14px; color: var(--muted); margin: 6px 0 14px;
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 20px; border-radius: 999px; font-weight: 600; font-size: 15px;
  background: var(--card2); border: 1px solid var(--border); transition: transform .08s;
}
.btn:active { transform: scale(.97); }
.btn.primary { background: var(--text); color: var(--bg); border-color: var(--text); }
.btn.accent { background: var(--accent); color: #0b0b0c; border-color: var(--accent); }
.btn.green { background: var(--green-bg); color: var(--green); border-color: transparent; }
.btn.red { background: var(--red-bg); color: var(--red); border-color: transparent; }
.btn.ghost { background: transparent; }
.btn.block { width: 100%; }
.btn.big { padding: 16px 22px; font-size: 17px; border-radius: 20px; }
.btn.sm { padding: 8px 14px; font-size: 13px; }
.btn[disabled] { opacity: .45; pointer-events: none; }
.btn-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }

/* ---------- chips ---------- */
.chip {
  display: inline-flex; align-items: center; gap: 6px; padding: 6px 12px; border-radius: 999px;
  background: var(--card2); border: 1px solid var(--border); font-size: 14px;
}
.chip.sm { padding: 3px 9px; font-size: 12px; }
.chip.green { background: var(--green-bg); color: var(--green); border-color: transparent; }
.chip.red { background: var(--red-bg); color: var(--red); border-color: transparent; }
.chip.amber { background: var(--amber-bg); color: var(--amber); border-color: transparent; }
.chip.accent { background: var(--accent-soft); color: var(--accent); border-color: transparent; }
.chip .zh { color: var(--muted); font-size: 13px; }
.chip.green .zh { color: inherit; opacity: .75; }
.chip.red .zh { color: inherit; opacity: .75; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip.fav { cursor: pointer; }
.chip.fav.on { background: var(--red-bg); color: var(--red); border-color: transparent; }

/* ---------- progress ---------- */
.bar { height: 6px; border-radius: 999px; background: var(--card2); overflow: hidden; }
.bar > i { display: block; height: 100%; background: var(--accent); border-radius: 999px; transition: width .3s; }
.bar > i.green { background: var(--green); }
.bar.thick { height: 10px; }
.bar.stack { position: relative; }
.bar.stack > i { position: absolute; left: 0; top: 0; }

/* ---------- stats header ---------- */
.stat-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.stat { text-align: center; padding: 14px 8px; }
.stat b { display: block; font-size: 30px; line-height: 1.1; font-weight: 700; }
.stat span { font-size: 13px; color: var(--muted); }
.stat-row.three { grid-template-columns: 1fr 1fr 1fr; }

/* ---------- lists ---------- */
.list { display: flex; flex-direction: column; gap: 8px; }
.item {
  display: flex; align-items: center; gap: 12px; padding: 12px 14px;
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-sm);
}
.item:active { background: var(--card2); }
.item .w { font-weight: 600; font-size: 16px; }
.item .zh { color: var(--muted); font-size: 14px; }
.item .meta { font-size: 12px; color: var(--dim); }
.dot { width: 10px; height: 10px; border-radius: 50%; background: var(--border); flex: none; }
.dot.learning { background: var(--amber); }
.dot.review { background: var(--accent); }
.dot.mastered { background: var(--green); }
.dot.due { box-shadow: 0 0 0 3px rgba(251, 191, 36, .25); }
.group-head { display: flex; align-items: center; justify-content: space-between; margin: 20px 0 10px; }
.group-head h3 { margin: 0; font-size: 17px; }
.bank-row { display: flex; flex-direction: column; gap: 8px; padding: 14px 16px; }
.bank-row .name { font-weight: 600; }
.bank-row .cnt { color: var(--muted); font-size: 13px; }
.sec-head { font-size: 13px; color: var(--muted); margin: 18px 4px 8px; font-weight: 600; }

/* ---------- search ---------- */
.search {
  display: flex; align-items: center; gap: 8px; background: var(--card); border: 1px solid var(--border);
  border-radius: 999px; padding: 6px 8px 6px 16px; margin-bottom: 14px;
}
.search input { flex: 1; background: none; border: 0; outline: 0; font-size: 16px; padding: 8px 0; min-width: 0; }
.search input::placeholder { color: var(--dim); }

/* ---------- word page ---------- */
.word-head { margin: 4px 0 8px; }
.word-title { font-size: 46px; font-weight: 600; letter-spacing: -.5px; line-height: 1.05; word-break: break-word; }
.word-title.long { font-size: 32px; }
.phonetic { color: var(--muted); font-size: 18px; margin-top: 6px; }
.gloss-card { font-size: 24px; padding: 22px 22px; line-height: 1.4; }
.gloss-card .full { font-size: 14px; color: var(--muted); margin-top: 8px; white-space: pre-line; }
.tabs {
  display: flex; background: var(--card); border: 1px solid var(--border); border-radius: 999px; padding: 4px;
  margin: 18px 0 16px;
}
.tabs button { flex: 1; padding: 10px 6px; border-radius: 999px; color: var(--muted); font-size: 15px; }
.tabs button.on { background: var(--bg); color: var(--text); box-shadow: 0 0 0 2px var(--accent) inset; }
.form-card { padding: 16px 18px; }
.form-card .fw { font-size: 18px; font-weight: 600; }
.form-card .ex { margin-top: 8px; font-size: 16px; text-decoration: underline dotted var(--dim); text-underline-offset: 4px; }
.form-card .exzh { color: var(--muted); font-size: 13px; margin-top: 2px; }
.speak {
  width: 40px; height: 40px; border-radius: 50%; background: var(--card2); border: 1px solid var(--border);
  display: inline-flex; align-items: center; justify-content: center; font-size: 16px; flex: none;
}
.speak.lg { width: 48px; height: 48px; font-size: 20px; }
.ex-card .topic { margin-bottom: 8px; }
.ex-card .en { font-size: 17px; text-decoration: underline dotted var(--dim); text-underline-offset: 4px; }
.ex-card .zh { color: var(--muted); font-size: 14px; margin-top: 4px; }
.pair-note { font-size: 14px; color: var(--muted); margin-top: 6px; }
.empty { color: var(--dim); text-align: center; padding: 30px 10px; }

/* ---------- learn ---------- */
.learn-top { display: flex; align-items: center; gap: 12px; margin: 6px 0 16px; }
.learn-top .bar { flex: 1; }
.flash {
  min-height: 360px; display: flex; flex-direction: column; justify-content: center; align-items: center;
  text-align: center; padding: 30px 22px; gap: 10px;
}
.flash .fw { font-size: 40px; font-weight: 600; letter-spacing: -.4px; word-break: break-word; }
.flash .fw.long { font-size: 28px; }
.flash .fz { font-size: 26px; color: var(--text); margin-top: 6px; }
.flash .fdef { color: var(--muted); font-size: 15px; margin-top: 6px; }
.flash .fex { color: var(--muted); font-size: 14px; margin-top: 10px; font-style: italic; }
.choices { display: flex; flex-direction: column; gap: 10px; margin-top: 14px; }
.choice {
  padding: 16px 18px; border-radius: 18px; background: var(--card); border: 1px solid var(--border);
  font-size: 18px; text-align: left; width: 100%;
}
.choice.correct { background: var(--green-bg); border-color: var(--green); color: var(--green); }
.choice.wrong { background: var(--red-bg); border-color: var(--red); color: var(--red); }
.choice[disabled] { opacity: .6; }
.choice.correct[disabled], .choice.wrong[disabled] { opacity: 1; }
.summary-num { font-size: 44px; font-weight: 700; }

/* ---------- forms ---------- */
.field { margin-bottom: 14px; }
.field label { display: block; font-size: 13px; color: var(--muted); margin-bottom: 6px; }
.input {
  width: 100%; padding: 12px 14px; border-radius: 14px; background: var(--bg2); border: 1px solid var(--border);
  outline: 0; font-size: 16px;
}
.input:focus { border-color: var(--accent); }
.input[readonly] { color: var(--muted); cursor: default; }
.input[readonly]:focus { border-color: var(--border); }
textarea.input { min-height: 70px; resize: vertical; }
.stepper { display: inline-flex; align-items: center; gap: 14px; }
.stepper button { width: 40px; height: 40px; border-radius: 50%; background: var(--card2); border: 1px solid var(--border); font-size: 20px; }
.stepper b { font-size: 22px; min-width: 32px; text-align: center; }
.check { display: flex; align-items: center; gap: 12px; padding: 12px 6px; border-bottom: 1px solid var(--border); }
.check:last-child { border-bottom: 0; }
.check input { width: 20px; height: 20px; accent-color: var(--accent); }
.check .name { flex: 1; }
.check .cnt { color: var(--dim); font-size: 13px; }
.err { color: var(--red); font-size: 14px; margin-top: 8px; }

/* ---------- login ---------- */
.login { min-height: 80vh; display: flex; flex-direction: column; justify-content: center; align-items: center; text-align: center; padding: 20px; }
.login h1 { font-size: 40px; margin: 12px 0 6px; letter-spacing: -.5px; }
.login p { color: var(--muted); max-width: 320px; }
.login .emoji { font-size: 70px; }

/* ---------- bottom nav ---------- */
#bottomnav {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 30; height: calc(var(--nav-h) + env(safe-area-inset-bottom));
  padding-bottom: env(safe-area-inset-bottom);
  background: var(--nav-bg); backdrop-filter: blur(14px); border-top: 1px solid var(--border);
  display: flex; justify-content: center;
}
#bottomnav a {
  flex: 1; max-width: 140px; display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 2px; font-size: 12px; color: var(--dim);
}
#bottomnav a .ico { font-size: 22px; }
#bottomnav a.on { color: var(--text); }

/* ---------- sheet ---------- */
#sheet-wrap { position: fixed; inset: 0; z-index: 50; }
.sheet-backdrop { position: absolute; inset: 0; background: rgba(0,0,0,.55); }
.sheet {
  position: absolute; left: 0; right: 0; bottom: 0; max-height: 86vh; overflow: auto;
  max-width: var(--maxw); margin: 0 auto; background: var(--card); border-radius: 26px 26px 0 0;
  border: 1px solid var(--border); padding: 14px 18px calc(24px + env(safe-area-inset-bottom));
  animation: up .22s ease-out;
}
@keyframes up { from { transform: translateY(40px); opacity: 0; } to { transform: none; opacity: 1; } }
.sheet-handle { width: 44px; height: 5px; border-radius: 3px; background: var(--border); margin: 0 auto 14px; }
.sheet h2 { margin: 0 0 12px; font-size: 20px; }

/* ---------- 今日任務 ---------- */
.task-card { border-color: var(--border); background: linear-gradient(180deg, var(--card2), var(--card)); }
.task-card.done { background: var(--green-bg); border-color: transparent; }
.task-card .bar > i { background: linear-gradient(90deg, var(--accent), #a5b8ff); }
.tile.on-red { box-shadow: 0 0 0 2px var(--red) inset; }
.tile.on-red .nm { color: var(--red); }

/* ---------- demo (teacher previewing the student view) ---------- */
#demo-banner {
  position: sticky; top: 0; z-index: 25; max-width: var(--maxw); margin: 0 auto 6px;
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  padding: 10px 16px; background: var(--amber-bg); color: var(--amber);
  border: 1px solid transparent; border-radius: 999px; font-size: 14px;
}
#demo-banner b { color: var(--text); }
#demo-banner .btn { background: var(--amber); color: #241a02; border-color: var(--amber); }
@media (min-width: 700px) { #demo-banner { margin-bottom: 10px; } }

/* ---------- toast ---------- */
#toast-wrap { position: fixed; left: 0; right: 0; bottom: calc(var(--nav-h) + 16px); z-index: 60; display: flex; flex-direction: column; align-items: center; gap: 8px; pointer-events: none; }
.toast { background: var(--text); color: var(--bg); padding: 10px 18px; border-radius: 999px; font-size: 14px; font-weight: 600; animation: up .2s; box-shadow: 0 6px 20px rgba(0,0,0,.4); }
.toast.err { background: var(--red); color: #fff; }

/* ---------- teacher ---------- */
table.tbl { width: 100%; border-collapse: collapse; font-size: 13px; }
.tbl th, .tbl td { padding: 9px 8px; border-bottom: 1px solid var(--border); text-align: left; white-space: nowrap; }
.tbl th { color: var(--muted); font-weight: 600; font-size: 12px; cursor: pointer; user-select: none; }
.tbl th.on { color: var(--text); }
.tbl tr:active td { background: var(--card2); }
.tbl td.num, .tbl th.num { text-align: right; }
.tbl tr[data-id] { cursor: pointer; }
.tbl tr.pending td { color: var(--dim); }
.t-filters { display: flex; flex-wrap: wrap; gap: 8px; justify-content: flex-end; }
.t-filters .select { max-width: 100%; }
.tbl-wrap { overflow-x: auto; margin: 0 -18px; padding: 0 18px; }
.bars { display: flex; align-items: flex-end; gap: 4px; height: 90px; }
.bars > div { flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: flex-end; height: 100%; gap: 4px; }
.bars i { display: block; width: 100%; background: var(--accent); border-radius: 4px 4px 0 0; min-height: 2px; }
.bars span { font-size: 9px; color: var(--dim); }
.heat {
  display: grid; grid-template-columns: repeat(12, 1fr); grid-auto-flow: column;
  grid-template-rows: repeat(7, 1fr); gap: 3px; max-width: 340px;  /* keep cells small on iPad */
}
.heat i { display: block; aspect-ratio: 1; border-radius: 3px; background: var(--card2); }
.heat i.l1 { background: var(--heat1); } .heat i.l2 { background: var(--heat2); } .heat i.l3 { background: var(--heat3); } .heat i.l4 { background: var(--green); }
.select {
  padding: 10px 36px 10px 14px; border-radius: 999px; background: var(--card); border: 1px solid var(--border);
  appearance: none; -webkit-appearance: none; outline: 0;
  background-image: linear-gradient(45deg, transparent 50%, var(--muted) 50%), linear-gradient(135deg, var(--muted) 50%, transparent 50%);
  background-position: calc(100% - 18px) 50%, calc(100% - 13px) 50%; background-size: 5px 5px; background-repeat: no-repeat;
}
.rank { width: 28px; text-align: center; font-weight: 700; color: var(--muted); }
.rank.top { color: var(--amber); }
.me { box-shadow: 0 0 0 2px var(--accent) inset; }

/* ---------- responsive grids (iPad ≥ 700px) ---------- */
.grid { display: grid; grid-template-columns: 1fr; gap: 10px; }
.tiles { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.tile {
  display: flex; flex-direction: column; gap: 4px; padding: 18px 18px; border-radius: var(--radius);
  background: var(--card); border: 1px solid var(--border); min-height: 96px; justify-content: center;
}
.tile:active { background: var(--card2); }
.tile .em { font-size: 30px; line-height: 1; }
.tile .nm { font-size: 18px; font-weight: 700; margin-top: 4px; }
.tile .sub { font-size: 13px; color: var(--muted); }
.tile.on { box-shadow: 0 0 0 2px var(--accent) inset; }
.seg { display: flex; gap: 6px; overflow-x: auto; padding-bottom: 4px; margin-bottom: 14px; scrollbar-width: none; }
.seg::-webkit-scrollbar { display: none; }
.seg button { flex: none; padding: 9px 18px; border-radius: 999px; background: var(--card); border: 1px solid var(--border); color: var(--muted); font-weight: 600; }
.seg button.on { background: var(--text); color: var(--bg); border-color: var(--text); }
.hero { display: grid; grid-template-columns: 1fr; gap: 12px; margin-bottom: 4px; }
.mini-stat { display: flex; align-items: center; gap: 12px; padding: 14px 16px; }
.mini-stat .em { font-size: 26px; }
.mini-stat b { font-size: 24px; line-height: 1; display: block; }
.mini-stat span { font-size: 12px; color: var(--muted); }
.mini-stat .bar { margin-top: 6px; }

@media (min-width: 700px) {
  #view { padding: 4px 28px 28px; }
  .word-title { font-size: 54px; }
  .flash { min-height: 420px; }
  .grid { grid-template-columns: 1fr 1fr; }
  .grid.three { grid-template-columns: 1fr 1fr 1fr; }
  .tiles { grid-template-columns: repeat(4, 1fr); }
  .hero { grid-template-columns: 1fr 1fr 1.4fr; }
  .stat-row { grid-template-columns: repeat(4, 1fr); }
  .stat-row.three { grid-template-columns: repeat(3, 1fr); }
  .btn-grid.wide { max-width: 620px; }
  .sheet { border-radius: 26px; bottom: auto; top: 8vh; max-height: 84vh; }
  .check-grid { display: grid; grid-template-columns: 1fr 1fr; column-gap: 20px; }
  .check-grid .check { border-bottom: 0; }
  #bottomnav a { max-width: 180px; }
}

/* ================================================================
   THEMES — site-wide, chosen by a teacher (老師 tab → 外觀主題).
   Each block only overrides tokens + a few signature rules, so every
   screen picks the look up automatically. Default = 午夜 (:root above).
   ================================================================ */

/* ---------- 紙本 Paper: warm off-white, serif headings, ink blue ---------- */
[data-theme="paper"] {
  --bg: #f4efe4; --bg2: #faf7f0; --card: #fffdf8; --card2: #efe8d9; --border: #d9d0bd;
  --text: #1f1b16; --muted: #6b6357; --dim: #9c9385;
  --accent: #1f4e8c; --accent-soft: rgba(31, 78, 140, .14);
  --green: #1f7a45; --green-bg: #dff0e5; --red: #b3261e; --red-bg: #f8e1df;
  --amber: #8a5f00; --amber-bg: #f6e9c4; --nav-bg: rgba(250, 247, 240, .94);
  --heat1: #cfe6d6; --heat2: #8fcaa4; --heat3: #4aa86e;
  --radius: 14px; --radius-sm: 10px; color-scheme: light;
}
[data-theme="paper"] .page-title, [data-theme="paper"] .word-title, [data-theme="paper"] .flash .fw,
[data-theme="paper"] .brand, [data-theme="paper"] .login h1, [data-theme="paper"] .form-card .fw {
  font-family: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, "Noto Serif TC", "Songti TC", serif;
  letter-spacing: 0;
}
[data-theme="paper"] .card, [data-theme="paper"] .item, [data-theme="paper"] .tile, [data-theme="paper"] .choice { box-shadow: 0 1px 2px rgba(60, 40, 10, .06); }
[data-theme="paper"] .gloss-card { background: #fbf4e3; }
[data-theme="paper"] .tabs button.on { background: var(--card); }
[data-theme="paper"] .sheet-backdrop { background: rgba(60, 45, 20, .35); }

/* ---------- 深海 Ocean: navy gradient, aqua accent, glass cards ---------- */
[data-theme="ocean"] {
  --bg: #071a2b; --bg2: #0b2238; --card: rgba(16, 44, 72, .72); --card2: #163a5c; --border: #24507a;
  --text: #e8f3ff; --muted: #8fb3d1; --dim: #5d81a3;
  --accent: #35d1e0; --accent-soft: rgba(53, 209, 224, .18);
  --green: #5ee6a3; --green-bg: #0f3d33; --red: #ff8585; --red-bg: #4a2030;
  --amber: #ffd166; --amber-bg: #4a3a12; --nav-bg: rgba(7, 26, 43, .88);
  --heat1: #12454d; --heat2: #1a7a86; --heat3: #26b5c4; --radius: 20px;
}
[data-theme="ocean"], [data-theme="ocean"] body {
  background: radial-gradient(1100px 600px at 15% -10%, #16436e 0%, transparent 60%),
              radial-gradient(900px 500px at 110% 20%, #0f5f70 0%, transparent 55%), var(--bg);
  background-attachment: fixed;
}
[data-theme="ocean"] .card, [data-theme="ocean"] .item, [data-theme="ocean"] .tile, [data-theme="ocean"] .choice, [data-theme="ocean"] .sheet { backdrop-filter: blur(10px); }
[data-theme="ocean"] .btn.primary { background: var(--accent); color: #062230; border-color: var(--accent); }
[data-theme="ocean"] #topbar { background: linear-gradient(rgba(7, 26, 43, .9) 70%, transparent); }
[data-theme="ocean"] .task-card .bar > i { background: linear-gradient(90deg, #35d1e0, #7ef0ff); }

/* ---------- 翠綠 Jade: light sage, emerald + gold ---------- */
[data-theme="jade"] {
  --bg: #edf3ee; --bg2: #f5f9f6; --card: #ffffff; --card2: #e3ece5; --border: #cddad0;
  --text: #14261b; --muted: #55705e; --dim: #8aa092;
  --accent: #1f8a5b; --accent-soft: rgba(31, 138, 91, .15);
  --green: #1f8a5b; --green-bg: #dbeee3; --red: #c0392b; --red-bg: #f8dfdc;
  --amber: #a67c0b; --amber-bg: #f5ecd0; --nav-bg: rgba(245, 249, 246, .94);
  --heat1: #cfe8d8; --heat2: #8ccfa9; --heat3: #3fae76;
  --radius: 22px; --radius-sm: 16px; color-scheme: light;
}
[data-theme="jade"] .btn.primary { background: var(--accent); color: #fff; border-color: var(--accent); }
[data-theme="jade"] .streak-pill { border-color: #d9b64a; background: #fff8e1; color: #6b5200; }
[data-theme="jade"] .tabs button.on { background: var(--card); box-shadow: 0 0 0 2px var(--accent) inset; }
[data-theme="jade"] .card, [data-theme="jade"] .item, [data-theme="jade"] .tile { box-shadow: 0 2px 6px rgba(20, 60, 40, .06); }
[data-theme="jade"] .tile.on-red { box-shadow: 0 0 0 2px var(--red) inset; }
[data-theme="jade"] .sheet-backdrop { background: rgba(20, 50, 35, .35); }
[data-theme="jade"] .task-card { background: linear-gradient(180deg, #ffffff, #eef6f0); }

/* ---------- 霓虹 Neon: pitch black, magenta + cyan, bold glow ---------- */
[data-theme="neon"] {
  --bg: #050507; --bg2: #0b0b10; --card: #101018; --card2: #181826; --border: #2a2a40;
  --text: #f5f5ff; --muted: #9d9dc0; --dim: #62628a;
  --accent: #ff2fa0; --accent-soft: rgba(255, 47, 160, .2);
  --green: #2fffb8; --green-bg: #0c3328; --red: #ff4d6d; --red-bg: #3d0f1e;
  --amber: #ffd23f; --amber-bg: #3a2f0a; --nav-bg: rgba(5, 5, 7, .92);
  --heat1: #2a1442; --heat2: #6b1f8a; --heat3: #c72fd8; --radius: 12px; --radius-sm: 8px;
}
[data-theme="neon"] .page-title, [data-theme="neon"] .word-title, [data-theme="neon"] .flash .fw, [data-theme="neon"] .brand b { font-weight: 800; letter-spacing: -.6px; }
[data-theme="neon"] .btn.primary { background: var(--accent); color: #fff; border-color: var(--accent); box-shadow: 0 0 18px rgba(255, 47, 160, .45); }
[data-theme="neon"] .btn.accent { background: #35f0ff; color: #041014; border-color: #35f0ff; box-shadow: 0 0 18px rgba(53, 240, 255, .35); }
[data-theme="neon"] .tabs button.on { box-shadow: 0 0 0 2px #35f0ff inset; }
[data-theme="neon"] .bar > i, [data-theme="neon"] .task-card .bar > i { background: linear-gradient(90deg, #ff2fa0, #35f0ff); }
[data-theme="neon"] .tile .nm { color: #35f0ff; }
[data-theme="neon"] .card, [data-theme="neon"] .item, [data-theme="neon"] .tile { border-color: #24243a; }
[data-theme="neon"] .streak-pill { border-color: #ffd23f; box-shadow: 0 0 12px rgba(255, 210, 63, .25); }
[data-theme="neon"] .chip.green { box-shadow: 0 0 10px rgba(47, 255, 184, .15); }

/* ---------- theme picker (老師 tab) ---------- */
.themes { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 10px; }
.theme-card {
  display: flex; flex-direction: column; align-items: flex-start; gap: 6px; padding: 12px; text-align: left;
  border-radius: var(--radius-sm); background: var(--card2); border: 2px solid var(--border);
}
.theme-card.on { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.theme-card .sw { display: flex; gap: 4px; width: 100%; height: 34px; border-radius: 8px; padding: 6px; border: 1px solid rgba(128, 128, 128, .25); }
.theme-card .sw i { flex: 1; border-radius: 4px; }
.theme-card b { font-size: 15px; }

/* ================================================================
   LAYOUT / INTERACTION MODES — site-wide, chosen by a teacher
   (老師 tab → 排版與操作模式). body.layout-<id> is set by app.js.
   ================================================================ */

/* ---------- 專注 Focus: no tab bar, ☰ menu, one big button, swipe cards ---------- */
body.layout-focus #bottomnav { display: none; }
body.layout-focus { padding-bottom: 24px; }
.focus-home { min-height: 62vh; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 18px; text-align: center; }
.ring { width: 150px; height: 150px; border-radius: 50%; border: 8px solid var(--accent); display: flex; flex-direction: column; align-items: center; justify-content: center; box-shadow: 0 0 0 10px var(--accent-soft); }
.ring b { font-size: 48px; line-height: 1; }
.ring span { font-size: 13px; color: var(--muted); }
.ring.sm { width: 64px; height: 64px; border-width: 4px; box-shadow: 0 0 0 5px var(--accent-soft); }
.ring.sm b { font-size: 16px; }
.focus-title { font-size: 26px; font-weight: 700; }
.focus-btn { padding: 20px 36px; font-size: 20px; border-radius: 999px; }
.focus-links { gap: 8px; color: var(--muted); font-size: 14px; justify-content: center; flex-wrap: wrap; }
.focus-links a { color: var(--text); }
.focus-browse { margin-top: 8px; }
.focus-browse .search { margin-bottom: 12px; }
.swipe-wrap { perspective: 900px; }
.swipe-card { min-height: 380px; display: flex; flex-direction: column; justify-content: center; text-align: center; padding: 30px 22px; position: relative; touch-action: pan-y; user-select: none; cursor: grab; }
.swipe-card .fw { font-size: 40px; font-weight: 600; word-break: break-word; }
.swipe-card .fw.long { font-size: 28px; }
.swipe-card .fz { font-size: 30px; }
.swipe-card .fdef, .swipe-card .fex { color: var(--muted); margin-top: 8px; }
.sw-tag { position: absolute; top: 18px; padding: 6px 14px; border-radius: 10px; font-weight: 800; font-size: 20px; opacity: 0; transition: opacity .15s; border: 3px solid; transform: rotate(-12deg); }
.sw-tag.left { left: 18px; color: var(--red); border-color: var(--red); }
.sw-tag.right { right: 18px; color: var(--green); border-color: var(--green); transform: rotate(12deg); }
.swipe-card.l .sw-tag.left, .swipe-card.r .sw-tag.right { opacity: 1; }

/* ---------- 詞典 Dictionary: top tab strip, sidebar of banks, dense rows ---------- */
body.layout-dictionary { padding-bottom: 24px; }
body.layout-dictionary #bottomnav {
  position: sticky; top: 66px; bottom: auto; height: 46px; padding: 0 18px; border-top: 0; border-bottom: 1px solid var(--border);
  background: var(--bg); backdrop-filter: none; max-width: var(--maxw); margin: 0 auto; justify-content: flex-start;
}
body.layout-dictionary #bottomnav a { flex: none; flex-direction: row; gap: 6px; font-size: 14px; padding: 0 14px; max-width: none; border-bottom: 2px solid transparent; }
body.layout-dictionary #bottomnav a.on { border-bottom-color: var(--accent); }
body.layout-dictionary #bottomnav a .ico { font-size: 16px; }
.dict-layout { display: grid; grid-template-columns: 1fr; gap: 16px; }
.dict-side { display: flex; flex-direction: column; gap: 2px; }
.dict-group { font-size: 12px; color: var(--muted); margin: 12px 4px 4px; font-weight: 600; }
.dict-bank { display: flex; justify-content: space-between; gap: 8px; padding: 8px 10px; border-radius: 10px; font-size: 14px; cursor: pointer; }
.dict-bank.on { background: var(--accent-soft); color: var(--accent); }
.dict-bank .cnt { color: var(--dim); font-size: 12px; }
@media (min-width: 900px) {
  .dict-layout { grid-template-columns: 250px 1fr; }
  .dict-side { position: sticky; top: 124px; align-self: start; max-height: calc(100vh - 150px); overflow: auto; }
}
@media (max-width: 899px) {
  .dict-side { flex-direction: row; overflow-x: auto; gap: 6px; padding-bottom: 6px; }
  .dict-side .section-title, .dict-group { display: none; }
  .dict-bank { flex: none; background: var(--card); border: 1px solid var(--border); white-space: nowrap; }
  .dict-bank .cnt { display: none; }
}
.dict-rows { display: flex; flex-direction: column; gap: 4px; }
.drow { display: flex; align-items: center; gap: 10px; padding: 8px 12px; border-radius: 10px; background: var(--card); border: 1px solid var(--border); flex-wrap: wrap; }
.drow .w { font-weight: 600; }
.drow .zh { color: var(--muted); font-size: 14px; flex: 1; min-width: 120px; text-align: left; background: none; border: 0; padding: 0; }
.drow .zh.blur { filter: blur(6px); cursor: pointer; }
.drow .acts { display: flex; gap: 6px; margin-left: auto; }
.drow .acts.wrap { flex-wrap: wrap; margin-left: 0; width: 100%; }
.drow.ok { background: var(--green-bg); }
.drow.bad { background: var(--red-bg); }

/* ---------- 競技 Arena: XP, timer, combo, confetti ---------- */
.arena-hero { background: linear-gradient(135deg, var(--card), var(--card2)); }
.arena-bar { margin-bottom: 10px; }
.arena-bar .bar > i { transition: width .1s linear; }
.choices.arena .choice { padding: 14px 16px; }
.confetti { position: fixed; inset: 0; pointer-events: none; z-index: 99; overflow: hidden; }
.confetti i { position: absolute; top: -12px; width: 10px; height: 14px; border-radius: 2px; animation: fall 2.2s ease-in forwards; }
@keyframes fall { to { transform: translateY(110vh) rotate(720deg); opacity: .2; } }

/* ---------- 聽寫 Dictation: typing ---------- */
.type-form { display: flex; gap: 8px; margin-top: 12px; }
.type-input { font-size: 20px; letter-spacing: .5px; flex: 1; min-width: 0; }
.type-diff { font-size: 26px; font-weight: 600; letter-spacing: 1px; }
.type-diff .ok { color: var(--green); }
.type-diff .bad { color: var(--red); text-decoration: underline; }

/* ---------- layout picker (老師 tab) ---------- */
.layouts { display: grid; grid-template-columns: repeat(auto-fill, minmax(170px, 1fr)); gap: 10px; }
.layout-card { display: flex; flex-direction: column; gap: 4px; padding: 12px; text-align: left; border-radius: var(--radius-sm); background: var(--card2); border: 2px solid var(--border); }
.layout-card.on { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.layout-card .ic { font-size: 26px; }
.layout-card b { font-size: 15px; }
.layout-card .d { font-size: 12px; color: var(--muted); line-height: 1.35; }

/* ---------- teacher vocabulary studio ---------- */
.teacher-sets-promo { display: flex; align-items: center; gap: 18px; padding: 24px; background: linear-gradient(115deg, var(--accent-soft), var(--card) 75%); }
.teacher-sets-promo b { font-size: 19px; }
.teacher-sets-promo p { margin: 6px 0 0; color: var(--muted); font-size: 14px; }
.set-promo-icon, .set-empty-icon { display: grid; place-items: center; width: 60px; height: 64px; flex: none; background: var(--accent-soft); color: var(--accent); border: 1px solid var(--border); border-radius: 17px; font-family: Georgia, serif; font-size: 32px; }
.set-promo-actions { display: flex; flex-direction: column; gap: 10px; align-items: center; flex: none; }
.set-text-link { color: var(--accent); font-size: 13px; font-weight: 600; padding: 7px 2px; text-underline-offset: 4px; }
.set-text-link:hover { text-decoration: underline; }
.set-workspace { padding-bottom: 14px; }
.set-workspace :is(button, a, input, textarea, select):focus-visible, .teacher-sets-promo a:focus-visible { outline: 2px solid var(--accent); outline-offset: 4px; }
.set-page-heading { display: flex; justify-content: space-between; align-items: center; gap: 16px; margin: 8px 0 26px; }
.set-page-heading .page-title { font-size: 30px; margin: 6px 0 8px; }
.set-page-heading p { margin: 0; font-size: 14px; }
.set-page-heading > .btn, .set-page-heading > .chip { flex: none; }
.set-eyebrow { color: var(--accent); font-size: 10px; font-weight: 700; letter-spacing: .16em; }
.set-list-info { display: flex; justify-content: space-between; gap: 12px; color: var(--muted); font-size: 12px; margin: 0 2px 12px; }
.set-saved-card { padding: 22px; }
.set-saved-card h2 { font-size: 21px; margin: 14px 0 8px; overflow-wrap: anywhere; }
.set-description { color: var(--muted); margin: 0 0 18px; font-size: 14px; white-space: pre-wrap; overflow-wrap: anywhere; }
.set-saved-footer { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-top: 22px; padding-top: 16px; border-top: 1px solid var(--border); flex-wrap: wrap; }
.set-delete-link { padding: 9px; color: var(--muted); font-size: 13px; }
.set-delete-link:hover { color: var(--red); }
.set-delete-confirm { background: var(--red-bg); border-radius: 12px; padding: 14px; margin-top: 14px; }
.set-delete-confirm p { margin: 0 0 12px; font-size: 14px; }
.set-empty-state { text-align: center; padding: 46px 20px; }
.set-empty-icon { margin: 0 auto 20px; width: 72px; height: 78px; }
.set-empty-state h2 { font-size: 22px; margin: 10px 0; }
.set-empty-state p { color: var(--muted); font-size: 14px; line-height: 1.8; margin-bottom: 24px; }
.set-editor-fields { min-width: 0; border: 0; margin: 0; padding: 0; }
.set-editor-fields:disabled { opacity: .7; }
.set-section { padding: 25px; margin-bottom: 20px; }
.set-section-heading { display: flex; gap: 12px; align-items: flex-start; margin-bottom: 22px; }
.set-section-heading h2 { margin: 0; font-size: 19px; }
.set-section-heading p { margin: 5px 0 0; color: var(--muted); font-size: 13px; line-height: 1.6; }
.set-section-heading > .set-text-link { flex: none; margin-left: auto; padding-top: 4px; }
.set-step { display: grid; place-items: center; border: 1px solid var(--border); background: var(--accent-soft); color: var(--accent); width: 29px; height: 29px; flex: none; border-radius: 9px; font-size: 13px; font-weight: 700; }
.set-required { color: var(--accent); }
.set-last-field { margin-bottom: 0; }
.set-import-tabs { display: flex; gap: 4px; background: var(--bg2); padding: 5px; border: 1px solid var(--border); border-radius: 12px; margin-bottom: 15px; }
.set-import-tabs button { flex: 1; padding: 10px 5px; font-size: 13px; border-radius: 8px; color: var(--muted); }
.set-import-tabs button.on { background: var(--card2); color: var(--text); box-shadow: 0 1px 3px #0002; }
.set-dropzone { border: 1px dashed var(--border); background: var(--bg2); border-radius: 16px; display: flex; align-items: center; flex-direction: column; gap: 10px; padding: 25px 16px; text-align: center; transition: border-color .15s, background .15s; }
.set-dropzone.dragover { background: var(--accent-soft); border-color: var(--accent); }
.set-upload-icon { display: grid; place-items: center; width: 38px; height: 38px; border: 1px solid var(--border); background: var(--card); border-radius: 12px; font-size: 25px; color: var(--accent); }
.set-dropzone b { font-size: 15px; }
.set-dropzone .btn { margin-top: 4px; }
.set-paste { margin: 8px 0 12px; font-size: 14px; tab-size: 16; }
.set-import-options { display: flex; justify-content: space-between; align-items: start; gap: 20px; margin-top: 14px; }
.set-import-options > span { font-size: 11px; line-height: 1.8; overflow-wrap: anywhere; }
.set-import-options > label { display: flex; flex-direction: column; gap: 5px; flex: none; font-size: 11px; }
.set-import-options .select { padding: 8px 10px; font-size: 12px; width: 156px; }
.set-notice { font-size: 13px; line-height: 1.7; padding: 13px 15px; border: 1px solid var(--border); border-radius: 12px; margin: 14px 0; background: var(--bg2); overflow-wrap: anywhere; }
.set-notice.success { color: var(--green); background: var(--green-bg); border-color: transparent; }
.set-notice.error, .set-save-error { color: var(--red); background: var(--red-bg); border: 1px solid var(--red); }
.set-notice ul, .set-save-error ul { margin: 8px 0 0; padding-left: 20px; }
.set-notice summary { cursor: pointer; }
.set-preview-heading { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin: 25px 0 14px; padding-top: 22px; border-top: 1px solid var(--border); }
.set-preview-heading h3 { display: flex; align-items: center; gap: 8px; font-size: 15px; margin: 0; }
.set-preview-empty { display: flex; align-items: center; flex-direction: column; gap: 6px; padding: 22px 12px; text-align: center; background: var(--bg2); border-radius: 12px; }
.set-preview-empty b { font-size: 14px; font-weight: 500; color: var(--muted); }
.set-preview-empty span { color: var(--muted); font-size: 12px; }
.set-word-list { scroll-margin-top: 100px; }
.set-word-row { display: grid; grid-template-columns: 23px minmax(0, 1fr) minmax(0, 1fr) 74px; align-items: start; gap: 10px; padding: 16px 0; border-top: 1px solid var(--border); }
.set-word-row:first-child { border-top: 0; padding-top: 2px; }
.set-word-row.invalid { border-left: 3px solid var(--red); padding-left: 10px; }
.set-word-number { color: var(--muted); font-size: 11px; padding-top: 34px; }
.set-word-field { display: block; min-width: 0; }
.set-word-field > span { display: block; margin: 0 0 6px; font-size: 11px; color: var(--muted); }
.set-word-field .input { border-radius: 9px; font-size: 14px; padding: 10px; }
.set-word-actions { display: flex; gap: 2px; align-items: center; padding-top: 25px; }
.set-word-more { font-size: 11px; color: var(--muted); padding: 9px 2px; white-space: nowrap; }
.set-word-more[aria-expanded="true"] { color: var(--accent); }
.set-word-remove { font-size: 21px; color: var(--muted); padding: 4px 7px; border-radius: 8px; }
.set-word-remove:hover { color: var(--red); background: var(--red-bg); }
.set-word-details { grid-column: 2 / -1; display: grid; grid-template-columns: 1fr 1fr; gap: 12px; background: var(--bg2); border: 1px solid var(--border); padding: 14px; border-radius: 12px; margin-top: 3px; }
.set-row-error { color: var(--red); font-size: 12px; grid-column: 2 / -1; }
.set-word-pages { display: flex; justify-content: space-between; align-items: center; gap: 10px; margin-top: 8px; }
.set-word-pages .btn { flex: none; }
.set-target-toolbar { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 10px; }
.set-target-toolbar .row { gap: 20px; }
.set-target-form { min-width: 0; border: 0; margin: 0 0 16px; padding: 0; }
.set-target-form legend { padding: 0 0 9px; color: var(--muted); font-size: 12px; font-weight: 600; }
.set-target-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 9px; }
.set-target { position: relative; display: flex; align-items: center; gap: 9px; border: 1px solid var(--border); border-radius: 12px; padding: 13px; background: var(--bg2); cursor: pointer; transition: background .15s, border-color .15s; }
.set-target.selected { background: var(--accent-soft); border-color: var(--accent); }
.set-target input { width: 17px; height: 17px; accent-color: var(--accent); margin: 0; flex: none; }
.set-target b { display: block; font-size: 14px; }
.set-target .grow > span { color: var(--muted); font-size: 10px; display: block; margin-top: 3px; overflow-wrap: anywhere; }
.set-target-tick { display: none; color: var(--accent); font-size: 12px; }
.set-target-note { border-top: 1px solid var(--border); padding-top: 14px; font-size: 11px; }
.set-publish-bar { position: sticky; bottom: calc(var(--nav-h) + env(safe-area-inset-bottom) + 10px); z-index: 10; display: flex; align-items: center; gap: 16px; padding: 16px 20px; border: 1px solid var(--border); border-radius: 17px; background: var(--card2); box-shadow: 0 8px 30px #0003; }
.set-publish-bar b { display: block; font-size: 14px; margin-bottom: 4px; }
.set-publish-bar .small { display: block; font-size: 11px; }
.set-publish-bar .btn { flex: none; }
.set-save-error { margin: 10px 0 18px; border-radius: 12px; padding: 15px 18px; font-size: 13px; scroll-margin-top: 100px; }
.layout-focus .set-publish-bar, .layout-dictionary .set-publish-bar { bottom: calc(env(safe-area-inset-bottom) + 12px); }
@media (max-width: 650px) {
  .teacher-sets-promo { flex-wrap: wrap; padding: 20px; gap: 13px; }
  .teacher-sets-promo .grow { flex-basis: calc(100% - 80px); }
  .set-promo-actions { flex-direction: row; justify-content: space-between; width: 100%; margin-top: 5px; }
  .teacher-sets-promo b { font-size: 17px; }
  .set-page-heading { align-items: flex-start; flex-wrap: wrap; margin-bottom: 20px; }
  .set-page-heading .page-title { font-size: 26px; }
  .set-section { padding: 18px 15px; }
  .set-section-heading { flex-wrap: wrap; gap: 10px; }
  .set-section-heading > .grow { flex-basis: calc(100% - 45px); }
  .set-section-heading > .set-text-link { margin-left: 39px; margin-top: -6px; }
  .set-target-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .set-import-options { flex-direction: column; gap: 12px; }
  .set-import-options > label { flex-direction: row; align-items: center; gap: 12px; }
  .set-import-tabs button { font-size: 12px; }
  .set-word-row { grid-template-columns: 18px minmax(0, 1fr) 65px; gap: 8px; }
  .set-word-w { grid-column: 2; grid-row: 1; }
  .set-word-zh { grid-column: 2; grid-row: 2; }
  .set-word-actions { grid-column: 3; grid-row: 1; }
  .set-word-details { grid-column: 2 / -1; grid-template-columns: 1fr; padding: 12px; }
  .set-word-pages { flex-wrap: wrap; }
  .set-word-pages > span { font-size: 10px; }
  .set-publish-bar { gap: 10px; padding: 13px; border-radius: 14px; }
  .set-publish-bar b { font-size: 12px; }
  .set-publish-bar .btn { font-size: 13px; padding: 12px 16px; }
  .set-publish-bar .small { font-size: 10px; }
  .set-list-info { flex-wrap: wrap; }
}

/* ================================================================
   QUESTION ENGINE — teaching card, questions, explanations, 筆記 tab
   ================================================================ */
.teach-card .tw { font-size: 36px; font-weight: 700; letter-spacing: -.3px; line-height: 1.1; }
.teach-card .tz { font-size: 22px; }
.forms-tbl { width: 100%; border-collapse: collapse; margin-top: 10px; font-size: 14px; }
.forms-tbl td { padding: 5px 8px 5px 0; border-bottom: 1px dashed var(--border); vertical-align: top; }
.forms-tbl tr:last-child td { border-bottom: 0; }
.teach-card .tex { margin-top: 10px; font-size: 16px; line-height: 1.5; }
.teach-card .tex .speak { vertical-align: middle; margin-left: 6px; width: 32px; height: 32px; font-size: 13px; }
mark { background: var(--accent-soft); color: var(--accent); padding: 0 3px; border-radius: 4px; font-weight: 600; }

.q-card { padding: 18px 20px; }
.q-prompt { font-size: 19px; font-weight: 600; margin-top: 8px; display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.q-sentence { font-size: 19px; line-height: 1.6; margin-top: 10px; }
.q-sentence.zh { font-size: 26px; }
.q-sentence .gap { display: inline-block; min-width: 90px; border-bottom: 2px solid var(--accent); color: transparent; }
.choices.long .choice { font-size: 15px; line-height: 1.45; padding: 12px 14px; }
.explain { margin-top: 12px; padding: 14px 16px; border-radius: var(--radius-sm); background: var(--card); border: 1px solid var(--border); border-left: 5px solid var(--green); }
.explain.bad { border-left-color: var(--red); }
.explain .ex-head { font-weight: 700; margin-bottom: 4px; }
.explain.ok .ex-head { color: var(--green); }
.explain.bad .ex-head { color: var(--red); }
.explain .ex-ans { font-size: 20px; font-weight: 600; margin-bottom: 6px; display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }

.skill-bars { display: grid; gap: 6px; margin-top: 8px; }
.skill-bars .sb { display: grid; grid-template-columns: 44px 1fr 48px; align-items: center; gap: 10px; font-size: 13px; }
.skill-bars .sb i { display: block; height: 8px; border-radius: 999px; background: var(--card2); }
.skill-bars .sb.part i { background: linear-gradient(90deg, var(--amber) 50%, var(--card2) 50%); }
.skill-bars .sb.ok i { background: var(--green); }
.skill-bars .ct { color: var(--muted); text-align: right; }

.seg { display: flex; background: var(--card); border: 1px solid var(--border); border-radius: 999px; padding: 4px; margin: 6px 0 14px; }
.seg a { flex: 1; text-align: center; padding: 9px 6px; border-radius: 999px; color: var(--muted); font-size: 14px; }
.seg a.on { background: var(--bg); color: var(--text); box-shadow: 0 0 0 2px var(--accent) inset; }
.seg a b { font-weight: 700; }
.note-txt { font-size: 14px; margin-top: 2px; white-space: pre-line; }
.mistake-row.cleared { opacity: .6; }
label.chip { cursor: pointer; }
label.chip input { accent-color: var(--accent); }